STS-121 Might Not Launch Until Late '06
Aero-News Analysis by Senior Correspondent Kevin R.C.
O'Brien
The hits just keep on coming for the Space Shuttle and NASA's
embattled administrators. According to a report by MSNBC's space
reporter James Oberg, problems with center fuel tanks make any
launch unlikely before early 2007.
While the destruction at NASA's tank-building facility in New
Orleans, and damage to a completed fuel tank there, is a problem, a
more serious and intractable difficulty is the shedding of
insulation from the center fuel tank.
Oberg obtained an internal NASA memo detailing the storm damage,
the problems with central tanks, and their likely consequences for
the launch schedule.
The Damaged Facility
The Michoud, Louisiana facility where Shuttle main tanks are
made is operated by giant prime contractor Lockheed Martin, and was
hard hit by the storm. The facility itself was damaged, a completed
main tank (that was destined, according to NASA's original Return
To Flight plans, to be mated with Atlantis... and launched in the
next couple of weeks) was damaged as well.
The real problem is that many of the workers' homes suffered
terribly, as did New Orleans area infrastructure. NASA is looking
at months before vital highway bridges are repaired (although the
speed with which contracts have been let is encouraging). Many of
the key workers in Michoud who didn't lose their homes have to
cross those bridges to get to work.
Key data is on computer systems that survived intact but are
without power, and for the time being NASA has no access to the
site to recover the data or computers. That will change when the
security and health situation permits, if authorities don't escort
NASA experts in sooner.
The port facility from which the tank travels to Canaveral took
a walloping, also, and is plugged with debris. But the real gating
factor in restoring Michoud to operation will probably the lack of
decent places for the workers to live. Over half of them are
displaced, some near other NASA facilities.
NASA is exploring options for making and preparing the tanks
elsewhere. A very large clean room is required, but this could be
done in the gigantic Vehicle Assembly Building, by setting up
overpressured and sealed tents inside.
The facility from which solid rocket boosters are shipped is in
Mississippi and also was hit by Katrina, but it was much less
heavily damaged than the Michoud facility. However, it shipped its
boosters by rail from New Orleans, and the rail terminal and
bridges are in poor shape.
If the Michoud facility was the only problem, NASA would be able
to hit its revised launch date of May 2006. (Pushed back from
March, which was where the initial assessment of the insulation
problem from Discovery's last flight slid it to from this month).
But the other damage in New Orleans complicates getting even a
perfect product from Michoud to the Gulf -- and thence around
Florida to Cape Canaveral. And if that's not bad enough, the
definition of what a "perfect product" is...isn't exactly
final.
The Tank Problem
The problem with delivering the tanks is only one worry for NASA
managers. The deeper problem is that they still aren't sure how to
make and insulate safe tanks.
NASA instrumented the tank used on STS-114 extensively,
expecting, among other things, to validate the Computational Fluid
Dynamics models they used to design the insulation. Except: the
data didn't match the theory. Instead of validating the model, they
invalidated it. Not only that, but the aerodynamic pressures around
critical components of the tank are not only not what the model
expected, they're not remotely steady. This means that the
aerodynamic assumptions that make the whole idea of using a CFD
model for this part of the design are out the window -- and leaves
the rocket scientists scratching their heads.
They will, of course, continue to reduce the data, and anything
may come of it, including fundamental new theoretical developments
extending the reach of CFD or improving our ability to model
transonic and supersonic flows in complex systems. But from NASA
bosses' viewpoint, this may come, but it cannot come soon enough to
prevent a problem.
While the results from instrumenting the tank are very
frustrating to NASA and space watchers right now, having a known
aerodynamic problem that's incredibly hard to deal with sure beats
having an unknown, and potentially devastating, aerodynamic
problem.
Why The Simple Solution -- Isn't
NASA continues to dismiss the "simple solution," of returning to
the earlier, safe, insulation that was used through 2002. That
insulation contains internationally banned chlorofluorocarbons
(CFCs) which contribute to ozone layer depletion. This sounds like
a simple solution, but it's apparently not legal.
Then, there's the simple fact that the "safe" insulation, like
the "unsafe" insulation, used to shed flakes on every flight. No
one thought that it was a serious hazard until the loss of the
orbiter Columbia in 2003 grabbed everybody's attention. It is quite
possible that the
And if the US backs off on CFC reduction, it will have great
problems getting China and India -- the two main producers of CFC
pollution now -- to cut back on their use of these chemicals.
The Consequences
These new delays -- and new expenses -- put the shuttle program
itself at risk. NASA leaders envisioned ending the shuttle program
in 2010, already. (Contractors previously believed that they can
keep the shuttles flying till 2030 or so). The new plan envisioned
only 15 to 28 more shuttle flights before retirement of the system
-- and that plan is already OBE (Overcome By Events).
There is no practical way now to deliver large items to the
International Space Station. This means that the station will
remain in caretaker mode for the foreseeable future, with
construction suspended.
Look for a lot of ideas to be kicked around over the next few
weeks and months. There is still a possibility some individual or
team can come up with a radical new solution to the insulation
problem. There's also a possibility, although a much lesser one,
that NASA may choose to accept certain risks it's been trying to
design out of a complex, risky system.
But for now, it looks like manned spaceflight in 2005 and 2006
will remain the province of Russia, China, and private operators in
suborbital flight. If you hang your hard hat in NASA's manned
spaceflight program, this is nothing short of a calamity. If you
hang your hat in, say, Mojave Spaceport, this is an
opportunity.